Circular knitting machine with a pivotable half dial

ABSTRACT

THE INVENTION RELATES TO CIRCULAR KNITTING MACHINES WITH A PIVOTABLE HALF DIAL IN WHICH TRANSFER JACKS ARE SLIDABLE INWARDLY AND OUTWARDLY BY MEANS OF A CAM PLATE. TO AVOID THAT A HOLE AND BULGE REMAINS IN THE TIP OF A STOCKING, THE TRANSFER JACKS ADJACENT TO THE EDGE ZONE OF THE HALF DIAL ARE RETRACTED TO A LESSER EXTENT THAN ALL THE REMAINING TRANSFER JACKS. THIS IS ACCOMPLISHED BY PROVIDING THE TRANSFER JACKS IN SAID EDGE ZONE WITH RECESSED SHOULDERS FOR COOPERATION WITH SAID CAM PLATE.

Oct. 5, 1971 u-rz ETAL 3,609,998

CIRCULAR KNITTING MACHINE WITH A PIVOTABLE HALF DIAL Filed Sept. 8, 1969 2 Sheets-Sheet 1 9 7 I {I g/// 1 n I g I 4 v 5 7 fig, L a

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\ o oo INVENTORS FRITZ HEINZ MUTZE KURT GERHARD BARTH CLAUS GOTTFRI ED WILLY KERTZSCHER ATTORNEYS Oct. 5, 1971 H MUTZE ETAL 3,609,998

CIRCULAR KNITTING MACHINE WITH A PIVOTABLE HALF DIAL Filed Sept. 8, 1969 2 Sheets-Sheet 2 INVENTORS FRITZ HEiNZ MUTZE KURT GERHARD BARTH cLAus GOTTFRIED WILLY KERTZSCHER ATTORN United States Patent Ofl1C 3,609,998 Patented Oct. 5, 1971 US. Cl. 66-95 4 Claims ABSTRACT OF THE DISCLOSURE The invention relates to circular knitting machines with a pivotable half dial in which transfer jacks are slidable inwardly and outwardly by means of a cam plate. To avoid that a hole and bulge remains in the tip of a stocking, the transfer jacks adjacent to the edge zone of the half dial are retracted to a lesser extent than all the remaining transfer jacks. This is accomplished by providing the transfer jacks in said edge zones with recessed shoulders for cooperation with said cam plate.

BACKGROUND OF THE INVENTION The invention relates to a circular knitting machine with a pivotable half dial. More specifically the invention relates to a single-cylinder circular-knitting machine having a half-dial pivotable with the top downwards. Transfer jacks are slidably mounted in pairs in radial slots of the half dial. When the sinker loops of one halfcylinder have been received or taken up by said transfer jacks, the jacks can be retracted into a position which provides for sufficient clearance between the jacks and the needles to permit the downwardly directed pivotal movement of the half-dial.

It has been proposed previously to retract all the transfer jacks to one common position. This position of the transfer jacks depends upon the number of loops which are knitted on to the edge needles of the half-cylinder before the start of the pivotal movement, that is the number of loops lying between the edge needle and the edge transfer jack.

After the sinker loops of the initial course have been received or taken up by the transfer jacks, a start is made immediately with the oscillating movement and thus also with the narrowing. This means that there is only one loop lying between the edge needle and the edge transfer jack. By edge transfer jack is meant a jack located adjacent the edge of the half dial as distinguished from the other transfer jacks which are distributed over the half dial. The edge transfer jack must consequently remain directly behind the back of the needle. Now, if all the transfer jacks are retracted into the same position a large free space for pivoting the half-dial is needed in the interior of the needle cylinder. However, the holding down sinkers and their internal guide, set an absolute limit to any increasing of the pivoting space.

It would be possible, after the sinker loops of the initial course have been taken up by the transfer jack to knit a number of courses in oscillating movement without narrowing so that the distance between the edge needles and the edge transfer jacks becomes great enough to prevent a collision between the transfer jacks and the holding down sinkers and their internal guide is avoided. However, the result of this is that a bulge and a small hole is formed in the finished stocking in the region of the edge needles.

In view of the above it is an object of the invention to avoid the formation of said hole in the stocking without interfering with the functional reliability of the pivotable half dial.

It is yet another object of the invention to control the movement of the transfer jacks individually so that certain transfer jacks are retracted differently than others.

Yet another object of the invention is to control the transfer jacks in such a manner that the edge transfer jacks can remain directly behind the needles and yet the necessary free pivoting space can be reduced.

SUMMARY OF THE INVENTION According to the invention there is provided a singlecylinder circular-knitting machine having a half-dial pivotable with its top downwards and provided with radial slots in which transfer jacks are slidably mounted in pairs, said transfer jacks being adapted to be retracted into a position which makes possible the downwardly directed pivotal movement of the half-dial when the sinker loops of one half-cylinder have been taken up, wherein during the pivotal movement the transfer jacks in the edge zones of the half-dial are disposed on a greater radius than the other transfer jacks.

The advantage of the invention is seen in that the inner transfer jack guide ring can be kept substantially in the previous form and the hole and the bulge in the region of the edge stitches is avoided.

In order that the invention may be clearly understood, it will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 shows a partial sectional view of the half-dial in the loop-receiving position,

FIG. 2 is a part-sectional plan view of FIG. 1,

FIGS. 3 to 8 show the transfer jacks and their control in the loop-receiving position of the half-dial,

FIGS. 9 to 12 show the transfer jacks and their control in the loop delivery or transfer position of the half-dial, and

FIG. 13 is a partial plan view of a cam box for controlling the transfer jacks.

Referring to the drawings, the single-cylinder circularknitting machine has a half-dial 1 which is pivotable in the direction of the arrow A with its top downwards for the purpose of closing the toe of a stocking. The pivoting takes place about a pivot bearing 2 of the halfdial 1 which is located in a tube 3 above the knockover plane of holding-down sinkers 4. The tube 3 is disposed coaxially with the needle cylinder and is rotatable. The half-dial 1 is pivoted by means of a rack 20 and a pinion 21 mounted in the tube 3. When the rack 20 is raised in the tube 3 the pinion rotates counterclockwise thereby pivoting the half-dial 1 in the direction of the arrow A. The fully pivoted position is shown (partly broken away) in dashed lines at the right hand side of FIG. 1. Lowering the rack 20 will pivot the half-dial 1 back into the top side up position as shown. One or more of the edge transfer jacks 5a, 6a which are located adjacent to the edge 1a of the half dial 1, are controlled differently than the other transfer jacks, as will be explained in more detail below.

The transfer jacks 5, 6 are disposed so as to slide radially in slots of the half-dial 1. As is known from earlier machines of the present type, each slot has a pair of jacks 5, 6 therein, each slidable, relative to the other and relative to the half-dial under impulses from a cam unit. For example FIGS. 3 and 4 show a pair of jacks in coincident positions; FIG. 6 shows jack 5 being returned by cam 19; FIG. 7 shows jack 5 repositioned; and FIG. 8 shows both jacks of this slot moved toward right. For such purposes each transfer jack 5, 6 has a butt 7 for control in the loop receiving position and butts 8 for control in the loop delivery or transfer position. Above the half-dial 1 there is held a cam box or plate 9 in a fixed position which carries cam parts to 14 (FIG. 13) for controlling the movement of the transfer jacks 5, 6 by rotating the tube 3 relative to the fixed cam plate 9.

The procedure for closing the toe with the abovedescribed mechanism begins with the receiving and clearing of the sinker loops or one half-cylinder by the transfer jacks 5, 6. Immediately afterwards the machine knits on in oscillating movement, one needle being brought into its inoperative position on both sides in each course. When a few courses have been knitted all the transfer jacks 5, 6 are retracted into a position permitting the pivoting of the half-dial 1 and avoiding collision with the holding-down sinkers 4.

The half-dial then is pivoted downwards. Approximately in the vertical position of the half-dial 1 the machine is changed to widening. Then, when enough courses have been knitted to cause the half-dial 1 to reach the horizontal loop delivery position, the transfer jacks 5, 6 deliver the sinker loops lying round them to the needles 16 of the complementary half-cylinder. These needles 16, which had not previously taken any part in the knitting process, now start to knit the hose, beginning at the toe. The machine continues to knit the foot, heel and other parts in circular movement as far as the welt with periodic adjustments of needle motions, as is known to the art.

This procedure makes it necessary for the transfer jacks 5, 6 to remain in the edge zones 17, 18 directly behind the needles 15, since the edge needles 15a, for example form only one loop. However, the inner position of the holding-down sinkers 4 absolutely limits the free pivoting space for the half-dial 1.

According to the invention, therefore, all the transfer jacks are retracted only to such an extent that they pivot past the holding-down sinkers 4 at an approximately constant distance corresponding to their radius of pivot.

This means that the transfer jacks 5, 6 in the edge zones 17, 18, which have only a small pivot radius, exploiting the tapered and offset shape of the holdingdown sinkers 4, can remain further forward than the transfer jacks 5, 6 with a greater pivot radius.

The method of controlling the transfer jacks 5, 6 will be explained as follows:

In the loop-receiving position the butts 7 are in the range of the cam parts 10 and 14. The transfer jacks-5, 6 assume the innermost positions as shown in FIG. 3. The cam part 10 pushes all the transfer jacks into a preparatory position (FIG. 4). There the transfer jacks 5 with long butts 7 are pushed outward into the region of the needles 15a by means of cam part 12 (FIG. 5). Transfer jacks 6 are maintained radially stationary, as jacks 5 are moved by cam 12, through the engagement of cam 11 with notched portions of the jacks. After receiving the sinker loops the transfer jacks 5 are retracted behind the pairs of needles 15 by the edge 19 of the cam box 9 (FIG. 6).-Up to this point of time the transfer jacks 5, 6 of the edge zone 17 and 18 (FIG. 2) are controlled in exactly the same way as all the other transfer jacks. After a few courses have been knitted in oscillating movement, the retraction part 13 (FIG. 7) is brought into engagement so that only the upper parts of the butts 7 are engaged. The butts 7 of the transfer jacks 5, 6 located in the edge zones 17, 18 are provided with shoulders in the upper part so that they are pushed back by the retraction parts 13 by an amount which is correspondingly smaller than the other transfer jacks 5, 6 which do not have shouldered butts 7 as shown in FIG. 8. On completion of the pivoting of the half-dial -1 the transfer jacks 5, 6 of the edge zones 17, 18 take up a position as shown in FIG. 9, whereas all the other transfer jacks 5, 6 are in an inward position (FIG. 10).

The advancing cam part 14 (FIG. 11) acts on the butts 8 of all transfer jacks (including those in the edge zones as well as the others, each of them having such butts, as noted) and pushes them forward to such an extent that delivery of the loop can take place in a way known to the art. The retraction cam part 13 assures that all the transfer jacks return to the neutral or rest position of FIG. 12.

The shouldering of the butts 7 in the region of the edge zones 17, 18 can be effected in accordance with the free pivoting space available from the outer side inwards gradually as well as in steps.

The invention has been described by way of example but it is intended to include all modifications and equivalents within the scope of the appended claims.

What we claim is:

1. A single-cylinder circular-knitting machine comprising:

(a) a pivotable half dial having substantially radially extending slots,

(b) pivoting means operatively connected to said halfdial,

(c) transfer jack means slidably mounted in pairs in said slots of the half dial, and

(d) cam control means arranged above the half dial for cooperation with cam follower means on the transfer jacks for advancing and retracting said transfer jacks in said slots, said cam follower means on transfer jacks arranged in edge zones of said half dial differing from the cam follower means on transfer jacks arranged outside said zones in such a manner that during the pivotal movement of the half dial the transfer jacks in said edge zones of the half dial are disposed radially outwardly on a greater radius than the transfer jacks outside said edge zones.

2. The single-cylinder circular knitting machine according to claim 1, wherein said cam follower means of the transfer jacks are butts protruding out of said slots and into cooperation with said cam control means.

3. The single-cylinder circular-knitting machine according to claim 1, wherein said cam follower means of said transfer jacks arranged in edge zones of the half dial are butts provided with step means on the outwardly directed side of said butts.

4. The single-cylinder circular knitting machine according to claim 1, wherein said pivoting means of the half dial comprise rack and pinion means arranged to cooperate for pivoting the half dial with its top downward when the sinker loops of one half cylinder have been taken up and the transfer jacks have been retracted.

References Cited UNITED STATES PATENTS 1,270,083 6/1918 Williams 66-187 1,270,084 6/1918 Williams 66-95 X 1,328,580 l/1920 Miller 66-95 FOREIGN PATENTS 286.142 2/1965 Netherlands 66-95 WILLIAM CARTER REYNOLDS, Primary Examiner 

